The present invention relates to a device that can be used in the evaluation or treatment of patients for hypernasality or nasal air emission during speech. The invention also relates to a method for evaluating or treating patients for such a condition.
Hypernasality and nasal air emission are speech characteristics due to a form of velopharyngeal dysfunction (also called velopharyngeal insufficiency or incompetence). In normal speech, the velum or soft palate elevates and closes against the posterior pharyngeal wall (the back wall of the throat). At the same time, the lateral pharyngeal walls move inward. These movements result in closure of the velopharyngeal valve, which closes off the nasal cavity from the oral cavity for normal speech. When the valve does not close completely, due to either structural or neurological abnormalities, air and sound escape into the nasal cavity during speech. This is a common problem for patients with a history of cleft palate, submucous cleft or various craniofacial syndromes. It is also commonly seen in patients with neuro-motor problems that affect muscle movement of velum and pharyngeal walls.
In evaluating hypernasality and nasal air emission, most speech pathologists rely on their ear for the assessment. Some have reported the use of a straw or listening tube to enhance the auditory signal. This can be accomplished by placing one end of the straw or tube at the tip of the patient""s nostril and the other end in the examiner""s ear. While this simple device works well in magnifying the auditory signal, the tube does not allow for hands-free use and only one person can listen at a time. In a therapeutic setting, where auditory biofeedback can greatly enhance therapy progress, it would be beneficial for the patient to be able to listen to the amplified sound coming from the nasal cavity at the same time as the therapist.
Other methods for evaluating hypernasality are more complex and expensive to use. Such methods may utilize spirometry measurement, airflow measurement with an anesthesia mask, ultrasonic devices, transducer devices, and oscilloscopic imaging. Various methods and devices for evaluating hypernasality or nasal airflow are disclosed in the following patents.
U.S. Pat. No. 3,752,929, issued to Fletcher on Aug. 14, 1973, describes a process and apparatus to independently measure auditory output from the nose and mouth. The apparatus uses microphones placed near the oral and nasal orifices. Quantitative electronic output for the nose and mouth are compared to determine the degree of nasality.
U.S. Pat. No. 4,862,503, issued to Rothenberg on Aug. 29, 1989, describes an apparatus and technique for extracting voice parameters from oral or combined oral and nasal airflow, using a tightly fitting mask. Voice parameters are detected and recorded with an electronic device.
U.S. Pat. No. 6,213,955 B1, issued to Karakasoglu et al. on Apr. 10, 2001, discloses an apparatus for measuring respiratory airflow from the nose and/or mouth of a patient, comprising a device having at least one acoustic duct receiving respiratory airflow. A sensor is exposed to the acoustic duct and senses turbulence, vibration and/or sound in the airflow in the acoustic duct to provide an electric output signal. Despite these advances in the art, there is a continuing need for a simple and effective device for evaluating and/or treating patients for hypernasality or nasal air emission during speech.
The present invention relates to a device for evaluating or treating a patient for hypernasality or nasal air emission during speech, said device comprising:
(a) a nosepiece for collecting nasal auditory output from the patient;
(b) a first listening device connected to the nosepiece to enable a therapist to receive the auditory output; and
(c) a second listening device connected to the nosepiece to enable the patient to receive the auditory output.
The invention also relates to a method for evaluating or treating a patient for hypernasality or nasal air emission during speech by using the above device.